Various types of knee braces are shown in the patent literature and are commercially available. Examples of such prior art braces are shown in the following U.S. Pat. No.: 4,370,977 (Mauldin et al), 4,372,298 (Lerman), 4,407,276 (Bledsoe), 4,481,941 (Rolfes), 4,487,200 (Feanny et al), 4,493,316 (Reed et al), 4,503,846 (Martin), 4,541,515 (Nishimura et al), 4,628,916 (Lerman et al.) and 4,715,363 (Detty). Examples of prior art knee braces which are commercially available are the following: the PRO-tector, PRO 24, and P.A.R. knee braces sold by Pro Orthopedic Devices, Inc. of Tucson, AZ, the ANDERSON KNEE STABLER protective knee brace sold by Omni Scientific, Inc of Martinez CA, the MCDAVID KNEEGUARD knee brace sold by McDavid Co. of Clarendon Hills, IL., the CTi brace sold by Innovation Sports, Inc. of Irvine, CA, the DONJOY FOUR-POINT brace sold by Donjoy, Inc. of Carlsbad, CA, and the LENNOX HILL brace sold by Lenox Hill Brace Co. of Long Island City, NY.
Many of the foregoing braces, while suitable for their intended purposes nevertheless suffer from a common problem, namely, they tend to migrate or slip down the leg when in use. Such action causes an inconvenience and potential problem for the wearer of the brace. In this regard the wearer must stop his/her activity to reposition the brace. Moreover, while the brace is out of position the wearer loses the maximum benefit of the support that the brace was designed to provide. Indeed, the brace may move so far out of position as to put the wearer in danger of injury.
As will be appreciated by those skilled in the art no matter how well designed or fitted a brace may be, it has to overcome two main obstacles to remain in position. The first obstacle is gravity, since it poses an unrelenting force pulling the brace down. The second obstacle is the constant expansion and contraction of the wearer's muscle tissue as the wearer moves about.
With the foregoing in mind manufacturers of knee braces have tried a variety of means to maintain proper brace position. In this regard many braces incorporate what can be called a "calf strap", which is a non-elastic strap coming across the top of the calf and cinching down tightly in the hope that it will not slide down over the largest part (sometimes called the "belly") of the calf. Another approach has been to use a cloth or neoprene under-sleeve, that is, a thin sleeve covering the leg under the entire length of the brace. This is done in the hope of providing a more frictionally engaging surface to the wearer's skin so that the brace will hold in position and not slip. In fact most commercially available braces are lined with some form of "non-slip" material, e.g., neoprene, nylon, etc. Unfortunately the foregoing approaches have not completely eliminated the migration or slipping problem. Even the lateral prophylactic braces which are now so popular in football exhibit migration or slipping problems, notwithstanding the variety of strapping techniques used thereby. In fact, short of using some adhesive, e.g., adhesive tape, nothing heretofore has seemed to eliminate the problem.